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(No Model.)

J. S. MAOARTHUR. METALLURGICAL FILTER.

No. 418,138. Patented Dec. 24, 1889.

fimitww nm 2 Wu Inn-un HI- W WITNESSES INVENTOR Attorney N. PETEBSL P'hnlmljmugmphcr, Washingwp, D. C.

UNITED STATES PATENT OFFICE.

JOHN STEYVART llfIACAR'lHUR, OF POLLOKSHIELDS, COUNTY OF RENFREVV, SCOTLAND.

M ETALLU RGICAL FILTER.

SPECIFICATION forming part of Letters Patent No. 418,138, dated December 24, 1889.

I Application filed November 13, 1889. Serial No. 330,195. (No model.

To all whom it may concern: jacent to the first filter of the series and ele- Be it known that I, JOHN STEWART MAC- 1 vated a sufficient distance to secure a proper ARTHUR, a subject of the Queen of Great Britflow of the liquid through the filters. This ain, residing at Pollokshields, in the county tank is provided with an outlet-tube 18 near 55 of Renfrew, Scotland, have invented a new its bottom, said tube being provided with a and useful Improvement in Metallurgical Filstop cock 19, and connected by pipe 20 with ters, of which the following is a specification. the inlet-tube of the first filter of the series.

This invention relates to a filter for pre- The zinc sponge, which constitutes the filtercipitating and separating precious metals ing material and precipitant, is preferably IO from solutions containing themsuch, for incomposed of fine threads or filaments of zinc stance, as chlorides, bromides, theosulphates, interlocked together. The zinc threads from (sometimes called hyposulphites,) or sulwhich the sponge is formed are cut by a turnphates obtained in the well-known Plattner, ing-tool from a series of zinc disks held bevon Patera, Russell, Ziervogel, and Augustine tween lathe-centers and turned; or the zinc 15 extracting processes. sponge may be formed by passing molten The object of the invention is to provide zinc, at a temperature just above the 1nelt a filter having a largeact-ive surface for the ing-point, through a fine sieve and allowmetals in solution. ing it to fall into water. This improved In the accompanying drawings, Figure 1 is zinc sponge presents a very large contact- 20 a sectional elevation of a series of these imsurface for the action of the solution, and

proved filters. Fig. 2 is a longitudinal vertiit does not become easily choked. Each concal section of a filtering apparatusv compristaming-vessel may be provided with a vering two of these improved filters constructed tical partition or partitions 21, as illustrated in modified form. Fig. 3 represents azinc in Fig. 2, whereby the vessel is divided into 25 filiform sponge, constituting the principal two or more compartments or filtering-chamfeature of this improved filter, the filaments bers. These partitions extend to a point near of the sponge being represented on an enthe bottom or top of the vessel, as the case larged scale. may be, or they are provided with holes near Similar numerals of reference indicate corthe top or near the bottom of the vessel. In 3o responding parts in the different figures. case the vessel has three or more filt-ering- This improved filter comprises a containchambers, the partitions are provided with ing-vessel 10 and a zinc sponge 11, disposed communicating openings, disposed altertherein. The zinc sponge is preferably supnately near the bottom and top of the vessel, ported on a perforated false bottom 12, diswhereby the passage of the solution is down- 35 posed within said vessel near the bottom ward through one of the filtering-chambers,

proper thereof. The vessel is provided with upward through the adjoining filtering-chaman inlet-tube 13 and an outlet-tube 1 1, the her, and downward again through the third inlet-tube being preferably disposed near the filtering-chamber, and so on. bottom of the vessel and the outlet-tube near In the use of this improved filtering appa- 9o 0 the top thereof, each of said tubes being proratus the solution containing the precious vided with a coupling-nut 15 when the vesmetal is placed in the tank 17 and the cock sels are used in series. 19 is opened. In case a series of separate fil- A number of these filters are preferably arters is employed, as represented in Fig. 1, the ranged in series, as represented in Fig. 1, solution passes from the tank through the 45 from six to ten being ordinarily employed. pipe 20 and into the first filter of the series, When so arranged, the filters are connected near the bottom thereof, beneath the false by pipes 16, which extend from the outlet bottom 12, thence upward through the zinc near the top of one vessel to the inlet near sponge within the filter, thence outward near the bottom of the adjacent vessel. A reserthe top of the first filter, thence through the 50 voir or tank 17 for containingthe solution connecting-pipe to the next filter of the seholding the precious metals is disposed adries, where it again enters near the bottom zinc sponge will remain therein.

and passes upward through the zinc sponge to the top of the second filter of the series, and so on. The metal which is not precipitated by the first filter is caught in the zinc sponge of the succeeding filters of the series.

In case filters having a number of compartments are employed, the solution is preferably admitted to the first compartment at the top thereof, and passes down through the zinc sponge contained in said compartment to near the bottom thereof, and thence passes into the second compartment and upward through the zinc sponge therein contained to near the top of said compartment, and thence downward through the next compartment, and so on through the several compartments of the compound filter, and thence to the next compound filter of the series and through its several compartments. The precious metal may be separated from the zinc sponge by distil-' lation, or the zinc sponge containing the precious metal maybe placed in a suitable sieve and subjected to a screening operation, preferably under Water. In this operation the greater part of the precious metal will pass through the sieve and the greater part of precious metal from a solution containing said metal, consisting of a vessel provided with a perforated false bottom, a zinc sponge within said vessel above said false bottom, and inlet and outlet openings above and below said sponge, substantially as described.

at. A metallurgical filter for separating a precious metal from a solution containing said metal, consisting of a vessel provided with a perforated false bottom, a filiform zinc sponge within said vessel above said false bottom, and inlet and outlet openings above and below said filiform sponge, substantially as described.

5. A metallurgical filtering apparatus for separating a precious metal from a solution containing said metal, consisting of a series of vessels, a zinc sponge in each of said vessels, pipes connecting the outlet-tube of one vessel of the series with the inlet-tube of the adjacent vessel of'the series, and a reservoir for supplying the solution to the first vessel of the series, substantially as described.

6. A metallurgical filtering apparatus for separating a precious metal from a solution containing said metal, consisting of a series of vessels, each of which has an inlet-tube near its bottom, an outlet-tube near its top, and a perforated false bottom above the inlet-tube, zinc sponges disposed in the several vessels, pipes connecting the inlet and outlet tubes of the several vessels, and a reservoir,

JOHN STEWART MAOARTHUR. Witnesses:

F. C. SoMEs, GORDON WILSON, Jun r. 

